Residents in Kiama Downs and Minnamurra have less than three months to move their phone and internet services to the National Broadband Network before copper services are retired.

Some residents were concerned they could face difficulties if not connected in time, but Telstra have maintained they will not be left behind.

Telstra area general manager Pamela Georgiou said copper-based services would be wound down from May 23.

"It's important for people to be aware that the change-over isn't automatic and customers need to place an order to move to the NBN. We're encouraging last-remaining customers to place an order with us by March 28."

Ms Georgiou said home phone customers needed to move to the NBN too.

"One common misconception we've encountered is that people think NBN is just for broadband.

"The reality is, customers in areas served by NBN Co's fixed line network need to sign up to a voice service on the NBN if they want to keep their landline."

One couple who have concerns about being switched over are Kiama Downs residents Andrew and Sheree Seamons.

Mr Seamons said he had experienced "never-ending problems".

"In early 2013 our contract with Telstra had expired, we approached Telstra to negotiate a new home service, only to be informed that we had no alternative but to switch to the new broadband system, as the old copper service was destined to be removed," he said.

"This was not a service that we required, but as our old ADSL plan did not exist any more we had no other option but to sign up.

"This occurred around February or March of 2013, we were told that connection time was around two to three weeks.

"After complaints to Telstra, NBN and the telecommunications ombudsman, the hardware was installed on December 23, some 10 months after the contract was signed.

"The bigger picture is once we all get switched off on May 23, no-one [who isn't connected] will be able to ring 000 during a blackout, for instance - what about the elderly?"

Mr Seamons said he had spent at least 50-60 hours attempting to rectify the situation.

"Yet Telstra has yet to switch us onto the broadband system, and are now blaming technical issues on their end for the further delay, and can not advise us as to a completion date."

A Telstra spokesperson said their team has been in contact with the Seamons and confirmed a connection date.

"We are investigating the cause of the delay."

However, Mr Seamons remained sceptical, saying one Telstra appointment had since been cancelled.

"Another broken promise, say one thing do another... I don't believe they'll turn up on March 4 (as scheduled)."

Telstra was investigating the case to understand how to improve processes.

"Customers with a valid NBN order who are yet to transition to the new network as of May 23 won't be disconnected.

"These customers will continue to have access to copper services until their NBN service is installed."

NBN Co spokesman Darren Rudd said they were working with phone and internet service providers so homes and businesses can order a service over the NBN as soon as possible.

"There is a small number of premises that require more complex installations and aren't yet able to order a service.

"NBN Co is working with Telstra on resolving this as soon as possible and the resident at Kiama Downs will be notified directly once they're able to order a service from their preferred internet and telephone provider."

Meanwhile, fixed wireless facilities are expected to be switched on from the middle of next year. NBN Co will lodge a planning proposal with the ouncil to install the technology, but the exact coverage areas will be subject to talks with the council.